Two-part rudder for ships



May 21,11 2 29. M, OERT 1,714,042

TWO-PART RUDDER FOR SHIPS Filed Nov. 17, 1925 P ace M... 21, 1929.

UNITED STATES 1,714,042 PATENT. OFFIC'E.

. max ona'rz, ormum-one, onmmr.

TWO-PART BUDDER FOB SHIPS.

Application m November 11. was, ser al no. assanand in Germany April 15, was.

In a previous patent the present applicant has described an invention for a two-part rudder, which, beingspaced away from the ships hull, is of'a cutwater form.

This apparatus is eharacterized-by-the feature that the oscillatable rear part of theof greatest thickness, so that when the helm is deflected, a form resembling that of the su porting plane of an aeroplane is obtained. he further developments of this invention form the subject-matter of the present apphcation. All the constructional forms serve to improve the action of the steering gear.

It is known that the oblique column of water thrown by the screw, in single screw I ships, always renders necessary a slight deflection of the rudder for the purpose of meanrudder body.

taining a course straight ahead. Efiorts have also been made by means of guiding devices, such as guide blades and the like fitted to the post, to impart to the screwwater-stream a guidance in the direction of its rotation. Such blade-like devices are, however, very sensitive.

In contrast thereto the applicant arranges in the simplest manner a-stationary guide body which constrains the stream of water to give up its twist or rotary direction of movement and flow towards the movable By the term longitudinal ships plane is meant in this specification the lane intersecting the ship vertically in a ongitudinal.

directlon passing through the keel.

A further improvement in the construction I may be obtained by making the entire device convex, as seen in a vertical section at right angles to the longitudinal ships plane, that is to say, by shaping it with arcuate lateral boundaries.

Fig. 1 shows the cross section form that is characteristic of the Oertz-rudder.

ing in front 0 it. It is recognizable therefrom that the outward edges of the two angularly. displaced rudder elements. of the movable rudder body have their maximum lateral convexity at about the centre of the rudder at the level of the propeller shaft and approach the longitudinal plane of the ship again towards the bottom and top.

Fig. 4 is a section'at the position A-B according to Fig. 3,

It will be seen that according to the known form of the Oertz-rudder the cross-section character of the fixedly connected parts ofthe rudder remains from the bottom up to the top always the same, the cross section taken at various heights of the rudder-body, however, does not remain symmetrical relative to the central line-of the rudder-body but changes according to the form of the angularly displaced surfaces in its distance from the central line, namely in such a manner that at the level of the propeller shaft the maximum lateral convexity of the' central line of the cross section of each of the two rudder elements lies above and beneath the propeller shaft whilst the central line of a cross section taken at the u perand lower end of the rudder body wou d correspond with the central line of the rudder body.

Fig. 5 shows a side elevation of the entire device. It will be seen therefrom that the stationary guide body has from the bottom up to the top always the same cross section character whilst the movable, rudder body pivoted thereto, shows, at the level of the propeller shaft a sectional line which lies somewhat beneath the section line A-B according to Fig. 3. The surface of the entire movable rudder body being not unitary and continuous but the part extending downwardly from the propeller shaft projecting and leaving the part extendin upwardly fromv the propeller shaft behin it is only possible to indicate a line .in the side elevation of Fig. 5,the line representing one edge.

Fi 6 is a section taken on line XX according to Fig. 4 and it is clearly shown thereby in which manner the various surfaces A further improvement in singe screw ships may now be employed on the rudder body, in such a way that the movable rudder body is not unitarily constructed but consists of two relatively displaced rudder elements, the rear edge of which exhibits the greatest lateral convexity, approximately inthe centre of the rudder at the level of the propeller shaft, and towards the top and bottom again approaches the longitudinal ships plane.

The adapting of a rudder to the screwwater-stream by shaping it with twisted surfaces is already known. As contrasted with this formation, wherein it is not a question of a stationary, thick guiding body formed like a cutwater in front, the applicant displaces two cutwater rudder elements relatively to one another in combination with a stationary cutwater-shaped guide body in inch a way as to obtain the best possible efect.

Fig. 5 shows the corresponding side elevation. e

The present invention has the particular advantage of being capable of being readily fitted to ships that are already finished, since for the rudder post only a sheath is required, which is constructed in accordance with the fundamental idea of the present invention,

and the back piece of the rudder may also be easily shaped or sheathed to cutwater form. a

Any sheathing of the stationary rudder post in this manner already brings with it a thickening which would come under the protection of the patent, as it is obviously not a question of maintaining exact dimensions, but these may be different from one case to another according to the nature of the ship. In the case of a simple sheathing of the rudder post for the purpose of better distribution of the incident water, a considerable effect is already obtained, which the applicant has been the first to recognize. I

The apparatus in all the methods of construction described, is obviously adapted not merely for lateral steering but also for depth form characterized in the individual claimis completely new in itself and is important for the attaining of a better action of the entire apparatus, the protection should expressly extend both to the use of the individual features by themselves according to the individual claim, and also to any desired combination of the individual features with one another.

What I claim is: v a

A two-part cutwater-shaped rudder for steering ships comprising a fixed rudder post,

the thickness of which exceeds the usual thickness as given by the classification re,- quirements, and an oscillatable rear part,

said rear part being pivoted to said fixed rudder post at substantially the maximum thickness of their'cross sections and the cross section of the rudder at its broadest part being greater than the section of the rudder post at its broadest part, and said oscilatable rear part consisting of two rudder elements which are arranged at an angle to one another on the common pivotal axisand having their rear edges diverging in opposite directlons from the central longitudinal plane of the ship, the maximum divergence occurring at the level of the propeller shaft.

In testimony whereof I affix my signature.

MAX OERTZ. 

